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Diffstat (limited to 'include/net/page_pool.h')
| -rw-r--r-- | include/net/page_pool.h | 402 |
1 files changed, 0 insertions, 402 deletions
diff --git a/include/net/page_pool.h b/include/net/page_pool.h deleted file mode 100644 index 126f9e294389..000000000000 --- a/include/net/page_pool.h +++ /dev/null @@ -1,402 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 - * - * page_pool.h - * Author: Jesper Dangaard Brouer <netoptimizer@brouer.com> - * Copyright (C) 2016 Red Hat, Inc. - */ - -/** - * DOC: page_pool allocator - * - * This page_pool allocator is optimized for the XDP mode that - * uses one-frame-per-page, but have fallbacks that act like the - * regular page allocator APIs. - * - * Basic use involve replacing alloc_pages() calls with the - * page_pool_alloc_pages() call. Drivers should likely use - * page_pool_dev_alloc_pages() replacing dev_alloc_pages(). - * - * API keeps track of in-flight pages, in-order to let API user know - * when it is safe to dealloactor page_pool object. Thus, API users - * must make sure to call page_pool_release_page() when a page is - * "leaving" the page_pool. Or call page_pool_put_page() where - * appropiate. For maintaining correct accounting. - * - * API user must only call page_pool_put_page() once on a page, as it - * will either recycle the page, or in case of elevated refcnt, it - * will release the DMA mapping and in-flight state accounting. We - * hope to lift this requirement in the future. - */ -#ifndef _NET_PAGE_POOL_H -#define _NET_PAGE_POOL_H - -#include <linux/mm.h> /* Needed by ptr_ring */ -#include <linux/ptr_ring.h> -#include <linux/dma-direction.h> - -#define PP_FLAG_DMA_MAP BIT(0) /* Should page_pool do the DMA - * map/unmap - */ -#define PP_FLAG_DMA_SYNC_DEV BIT(1) /* If set all pages that the driver gets - * from page_pool will be - * DMA-synced-for-device according to - * the length provided by the device - * driver. - * Please note DMA-sync-for-CPU is still - * device driver responsibility - */ -#define PP_FLAG_PAGE_FRAG BIT(2) /* for page frag feature */ -#define PP_FLAG_ALL (PP_FLAG_DMA_MAP |\ - PP_FLAG_DMA_SYNC_DEV |\ - PP_FLAG_PAGE_FRAG) - -/* - * Fast allocation side cache array/stack - * - * The cache size and refill watermark is related to the network - * use-case. The NAPI budget is 64 packets. After a NAPI poll the RX - * ring is usually refilled and the max consumed elements will be 64, - * thus a natural max size of objects needed in the cache. - * - * Keeping room for more objects, is due to XDP_DROP use-case. As - * XDP_DROP allows the opportunity to recycle objects directly into - * this array, as it shares the same softirq/NAPI protection. If - * cache is already full (or partly full) then the XDP_DROP recycles - * would have to take a slower code path. - */ -#define PP_ALLOC_CACHE_SIZE 128 -#define PP_ALLOC_CACHE_REFILL 64 -struct pp_alloc_cache { - u32 count; - struct page *cache[PP_ALLOC_CACHE_SIZE]; -}; - -struct page_pool_params { - unsigned int flags; - unsigned int order; - unsigned int pool_size; - int nid; /* Numa node id to allocate from pages from */ - struct device *dev; /* device, for DMA pre-mapping purposes */ - struct napi_struct *napi; /* Sole consumer of pages, otherwise NULL */ - enum dma_data_direction dma_dir; /* DMA mapping direction */ - unsigned int max_len; /* max DMA sync memory size */ - unsigned int offset; /* DMA addr offset */ - void (*init_callback)(struct page *page, void *arg); - void *init_arg; -}; - -#ifdef CONFIG_PAGE_POOL_STATS -struct page_pool_alloc_stats { - u64 fast; /* fast path allocations */ - u64 slow; /* slow-path order 0 allocations */ - u64 slow_high_order; /* slow-path high order allocations */ - u64 empty; /* failed refills due to empty ptr ring, forcing - * slow path allocation - */ - u64 refill; /* allocations via successful refill */ - u64 waive; /* failed refills due to numa zone mismatch */ -}; - -struct page_pool_recycle_stats { - u64 cached; /* recycling placed page in the cache. */ - u64 cache_full; /* cache was full */ - u64 ring; /* recycling placed page back into ptr ring */ - u64 ring_full; /* page was released from page-pool because - * PTR ring was full. - */ - u64 released_refcnt; /* page released because of elevated - * refcnt - */ -}; - -/* This struct wraps the above stats structs so users of the - * page_pool_get_stats API can pass a single argument when requesting the - * stats for the page pool. - */ -struct page_pool_stats { - struct page_pool_alloc_stats alloc_stats; - struct page_pool_recycle_stats recycle_stats; -}; - -int page_pool_ethtool_stats_get_count(void); -u8 *page_pool_ethtool_stats_get_strings(u8 *data); -u64 *page_pool_ethtool_stats_get(u64 *data, void *stats); - -/* - * Drivers that wish to harvest page pool stats and report them to users - * (perhaps via ethtool, debugfs, or another mechanism) can allocate a - * struct page_pool_stats call page_pool_get_stats to get stats for the specified pool. - */ -bool page_pool_get_stats(struct page_pool *pool, - struct page_pool_stats *stats); -#else - -static inline int page_pool_ethtool_stats_get_count(void) -{ - return 0; -} - -static inline u8 *page_pool_ethtool_stats_get_strings(u8 *data) -{ - return data; -} - -static inline u64 *page_pool_ethtool_stats_get(u64 *data, void *stats) -{ - return data; -} - -#endif - -struct page_pool { - struct page_pool_params p; - - struct delayed_work release_dw; - void (*disconnect)(void *); - unsigned long defer_start; - unsigned long defer_warn; - - u32 pages_state_hold_cnt; - unsigned int frag_offset; - struct page *frag_page; - long frag_users; - -#ifdef CONFIG_PAGE_POOL_STATS - /* these stats are incremented while in softirq context */ - struct page_pool_alloc_stats alloc_stats; -#endif - u32 xdp_mem_id; - - /* - * Data structure for allocation side - * - * Drivers allocation side usually already perform some kind - * of resource protection. Piggyback on this protection, and - * require driver to protect allocation side. - * - * For NIC drivers this means, allocate a page_pool per - * RX-queue. As the RX-queue is already protected by - * Softirq/BH scheduling and napi_schedule. NAPI schedule - * guarantee that a single napi_struct will only be scheduled - * on a single CPU (see napi_schedule). - */ - struct pp_alloc_cache alloc ____cacheline_aligned_in_smp; - - /* Data structure for storing recycled pages. - * - * Returning/freeing pages is more complicated synchronization - * wise, because free's can happen on remote CPUs, with no - * association with allocation resource. - * - * Use ptr_ring, as it separates consumer and producer - * effeciently, it a way that doesn't bounce cache-lines. - * - * TODO: Implement bulk return pages into this structure. - */ - struct ptr_ring ring; - -#ifdef CONFIG_PAGE_POOL_STATS - /* recycle stats are per-cpu to avoid locking */ - struct page_pool_recycle_stats __percpu *recycle_stats; -#endif - atomic_t pages_state_release_cnt; - - /* A page_pool is strictly tied to a single RX-queue being - * protected by NAPI, due to above pp_alloc_cache. This - * refcnt serves purpose is to simplify drivers error handling. - */ - refcount_t user_cnt; - - u64 destroy_cnt; -}; - -struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp); - -static inline struct page *page_pool_dev_alloc_pages(struct page_pool *pool) -{ - gfp_t gfp = (GFP_ATOMIC | __GFP_NOWARN); - - return page_pool_alloc_pages(pool, gfp); -} - -struct page *page_pool_alloc_frag(struct page_pool *pool, unsigned int *offset, - unsigned int size, gfp_t gfp); - -static inline struct page *page_pool_dev_alloc_frag(struct page_pool *pool, - unsigned int *offset, - unsigned int size) -{ - gfp_t gfp = (GFP_ATOMIC | __GFP_NOWARN); - - return page_pool_alloc_frag(pool, offset, size, gfp); -} - -/* get the stored dma direction. A driver might decide to treat this locally and - * avoid the extra cache line from page_pool to determine the direction - */ -static -inline enum dma_data_direction page_pool_get_dma_dir(struct page_pool *pool) -{ - return pool->p.dma_dir; -} - -bool page_pool_return_skb_page(struct page *page, bool napi_safe); - -struct page_pool *page_pool_create(const struct page_pool_params *params); - -struct xdp_mem_info; - -#ifdef CONFIG_PAGE_POOL -void page_pool_unlink_napi(struct page_pool *pool); -void page_pool_destroy(struct page_pool *pool); -void page_pool_use_xdp_mem(struct page_pool *pool, void (*disconnect)(void *), - struct xdp_mem_info *mem); -void page_pool_release_page(struct page_pool *pool, struct page *page); -void page_pool_put_page_bulk(struct page_pool *pool, void **data, - int count); -#else -static inline void page_pool_unlink_napi(struct page_pool *pool) -{ -} - -static inline void page_pool_destroy(struct page_pool *pool) -{ -} - -static inline void page_pool_use_xdp_mem(struct page_pool *pool, - void (*disconnect)(void *), - struct xdp_mem_info *mem) -{ -} -static inline void page_pool_release_page(struct page_pool *pool, - struct page *page) -{ -} - -static inline void page_pool_put_page_bulk(struct page_pool *pool, void **data, - int count) -{ -} -#endif - -void page_pool_put_defragged_page(struct page_pool *pool, struct page *page, - unsigned int dma_sync_size, - bool allow_direct); - -/* pp_frag_count represents the number of writers who can update the page - * either by updating skb->data or via DMA mappings for the device. - * We can't rely on the page refcnt for that as we don't know who might be - * holding page references and we can't reliably destroy or sync DMA mappings - * of the fragments. - * - * When pp_frag_count reaches 0 we can either recycle the page if the page - * refcnt is 1 or return it back to the memory allocator and destroy any - * mappings we have. - */ -static inline void page_pool_fragment_page(struct page *page, long nr) -{ - atomic_long_set(&page->pp_frag_count, nr); -} - -static inline long page_pool_defrag_page(struct page *page, long nr) -{ - long ret; - - /* If nr == pp_frag_count then we have cleared all remaining - * references to the page. No need to actually overwrite it, instead - * we can leave this to be overwritten by the calling function. - * - * The main advantage to doing this is that an atomic_read is - * generally a much cheaper operation than an atomic update, - * especially when dealing with a page that may be partitioned - * into only 2 or 3 pieces. - */ - if (atomic_long_read(&page->pp_frag_count) == nr) - return 0; - - ret = atomic_long_sub_return(nr, &page->pp_frag_count); - WARN_ON(ret < 0); - return ret; -} - -static inline bool page_pool_is_last_frag(struct page_pool *pool, - struct page *page) -{ - /* If fragments aren't enabled or count is 0 we were the last user */ - return !(pool->p.flags & PP_FLAG_PAGE_FRAG) || - (page_pool_defrag_page(page, 1) == 0); -} - -static inline void page_pool_put_page(struct page_pool *pool, - struct page *page, - unsigned int dma_sync_size, - bool allow_direct) -{ - /* When page_pool isn't compiled-in, net/core/xdp.c doesn't - * allow registering MEM_TYPE_PAGE_POOL, but shield linker. - */ -#ifdef CONFIG_PAGE_POOL - if (!page_pool_is_last_frag(pool, page)) - return; - - page_pool_put_defragged_page(pool, page, dma_sync_size, allow_direct); -#endif -} - -/* Same as above but will try to sync the entire area pool->max_len */ -static inline void page_pool_put_full_page(struct page_pool *pool, - struct page *page, bool allow_direct) -{ - page_pool_put_page(pool, page, -1, allow_direct); -} - -/* Same as above but the caller must guarantee safe context. e.g NAPI */ -static inline void page_pool_recycle_direct(struct page_pool *pool, - struct page *page) -{ - page_pool_put_full_page(pool, page, true); -} - -#define PAGE_POOL_DMA_USE_PP_FRAG_COUNT \ - (sizeof(dma_addr_t) > sizeof(unsigned long)) - -static inline dma_addr_t page_pool_get_dma_addr(struct page *page) -{ - dma_addr_t ret = page->dma_addr; - - if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT) - ret |= (dma_addr_t)page->dma_addr_upper << 16 << 16; - - return ret; -} - -static inline void page_pool_set_dma_addr(struct page *page, dma_addr_t addr) -{ - page->dma_addr = addr; - if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT) - page->dma_addr_upper = upper_32_bits(addr); -} - -static inline bool is_page_pool_compiled_in(void) -{ -#ifdef CONFIG_PAGE_POOL - return true; -#else - return false; -#endif -} - -static inline bool page_pool_put(struct page_pool *pool) -{ - return refcount_dec_and_test(&pool->user_cnt); -} - -/* Caller must provide appropriate safe context, e.g. NAPI. */ -void page_pool_update_nid(struct page_pool *pool, int new_nid); -static inline void page_pool_nid_changed(struct page_pool *pool, int new_nid) -{ - if (unlikely(pool->p.nid != new_nid)) - page_pool_update_nid(pool, new_nid); -} - -#endif /* _NET_PAGE_POOL_H */ |